Inertial measurement unit (IMU)
An Inertial measurement unit (IMU) is an electronic device which measures and reports body's inertia, orientation and angular speed. It accomplishes these tasks with use of several instruments such as accelerometers, gyroscopes and magnetometers all of which have capabilities of measuring data in three degrees of freedom. IMU as an instrument is essential in the engineering world since it is a crucial part of any project. Areas where IMUs are quite important are those where we have use for direct feedback on the speed, orientation and position of the body. That makes it crucial in use for design of robots, drones, satellites etc. Each sensor in the IMU supports a wide spectrum of ranges: the accelerometer’s scale can be set to ± 2, 4, 8, or 16 g, the gyroscope supports ± 245, 500, and 2000 degrees per second, and the magnetometer has full-scale ranges of ± 4, 8, 12, or 16 gauss.
Figure 4: LSM9DS1 Sparkfun IMU
IMU that group E2023 used on their bachelor thesis is LSM9DS1 Sparkfun IMU. It is a versatile, motion-sensing system in a chip. It houses a 3-axis accelerometer, 3-axis gyroscope, and 3-axis magnetometer which combines in nine degrees of freedom (9DOF). 16-bit data output is available via I2C and SPI communication protocols. Also included is the temperature sensor which is embedded in the chip. From this one can conclude that LSM9DS1 is perfectly suitable instrument for measuring movement for robots and drones, since it has instruments perfect for that task. It is possible to both write and read from this IMU, on how it can be done one can visit official net site of SparkFun and find an example of Arduino code.
Figure 5: Pinout position and function